This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C xc2xa7119 from an application entitled Hi-Fi audio Signal Recording/Playback Apparatus Using Video Heads earlier filed in the Korean industrial Property Office on Mar. 14, 1998, and there duly assigned Ser. No. 98-8645 by that Office.
1. Field of the Invention
The present invention relates to an image and audio signal recording/playback apparatus, and more particularly, to a high fidelity (Hi-Fi) audio signal recording/playback apparatus in which a Hi-Fi audio signal is recorded and reproduced using conventional video heads, not using an extra Hi-Fi audio head.
2. Description of the Related Art
In a VHS type Hi-Fi video cassette recorder (VCR), a Hi-Fi audio head is attached to a drum with a video head, such that it is able to move along the same circumference of a circle together with the video heads. The Hi-Fi audio heads modulate the frequency of an audio signal to record the modulated signal on an embedded layer of a video track, and reads the Hi-Fi audio signal recorded in-depth on the video track.
Thus, an audio signal is recorded on a sound track by a conventional fixed audio head and a frequency-modulated (FM) audio signal is recorded in the embedded layer of the video track by a Hi-Fi audio head. Also, a video signal is recorded in a top layer of the same video track, which is shown in FIG. 1. However, to be exact a color signal of the signals recorded by the video head has a low frequency, so the color signal is recorded upto the deep layer, as shown in FIG. 2A. However, because the level of the color signal to be recorded is lower than that of a luminance signal by approximately 10 dB or more, the recorded color signal is not able to erase the Hi-Fi audio signal recorded in the deep layer as shown in FIG. 2B.
FIGS. 3A and 3B show the structure of a video/Hi-Fi audio signal recording apparatus of a conventional Hi-Fi audio VCR. In the case of a Hi-Fi stereo audio system adopting two channels, a frequency-modulated carrier signal for the left channel (L) (1.3 MHz) is different than that for the right channel (R) (1.7 MHz). Thus, for the recording of a Hi-Fi signal (see FIG. 3B), the modulated Hi-Fi signals from the L and R channels are mixed by a mixer 304, and then amplified by a preamplifier 305 only for a Hi-Fi audio signal to the level required for recording. Then, the mixed Hi-Fi audio signal is recorded in the embedded layer of the video track by a head 306 only for a Hi-Fi audio signal, which is attached to a drum.
Then, for the recording of a video signal (see FIG. 3A), an FM luminance signal Y and a color signal C converted to a low frequency band are mixed by a mixer 301, and then amplified by a video pre-amplifier 302 to the level required for the recording. Then, the amplified video signal is recorded in the top layer of the video track by video heads 303 attached to the drum.
As shown in FIGS. 4A and 4B, which show the structure of a video/Hi-Fi audio playback apparatus of the conventional Hi-Fi audio VCR, for the playback, the video signal and the Hi-Fi audio signal recorded on the video track are read by video heads 400A and Hi-Fi audio heads 400B and then amplified by a video pre-amplifier 401 and a Hi-Fi audio pre-amplifier 411, respectively. Then, the amplified video signal is demodulated through equalizers (EQs) 402 and 403 and demodulators (DEMODs) 404 and 405, and the demodulated video signals passed through the demodulators 404 and 405 are mixed by a mixer 406 to playback the video signal. Also, the Hi-Fi audio signal is divided for L and R channels by band pass filters (BPFs) 412 and 413, and then demodulated by demodulators (DEMODs) 414 and 415, respectively.
As described above, the conventional VCR requires an additional pre-amplifier as well as an additional head only for a Hi-Fi audio signal, besides the video head attached to a drum, for the record/playback of a Hi-Fi audio signal, thereby increasing the manufacturing cost. In particular, the expensive head for only a Hi-Fi audio signal attached to the drum and increased man-hour for the assembly process increase the manufacturing cost.
Examples of convention audio and video recording devices, incorporated herein by reference, are found in U.S. Pat. No. 4,752,832 to Seiji Higurashi entitled Vide And Audio Signal Recording And/Or Reproducing Apparatus, U.S. Pat. No. 4,757,394 to Kaneyuki Okamoto et al entitled Auto-Tracking Apparatus Of A Magnetic Recording/Reproducing Apparatus, U.S. Pat. No. 4,758,903 to Takaharu Noguchi et al. entitled Apparatus For Recording And Reproducing Video Signal and Digital Signal Other Than Video Signal, U.S. Pat. No. 5,392,165 to Yukiharu Hosono et al. entitled Apparatus For Recording audio And Video Signal, and U.S. Pat. No. 5,572,331 to Jae-cheon Yu entitled Video Signal Recording Format, Deep Recording/Reproducing Apparatus And Method Therefor.
To solve the above problems, it is an object of the present invention to provide a high fidelity (Hi-Fi) audio recording apparatus capable of recording a Hi-Fi audio signal using a video head without the need for a head only for a Hi-Fi audio signal.
It is another object of the present invention to provide a Hi-Fi audio playback apparatus capable of reproducing a Hi-Fi audio signal using a video head without the need for a head only for a Hi-Fi audio signal.
To achieve the first object of the present invention, there is provided an apparatus for recording a modulated video signal and a modulated high fidelity (Hi-Fi) audio signal using video heads, comprising: a mixer for mixing the modulated video signal and the modulated Hi-Fi audio signal to output a mixed video/audio signal to be recorded; a recording amplifier for receiving the mixed video/audio signal and amplifying the mixed video/audio signal with a predetermined gain to output a recording current required for the recording; and heads for generating a magnetic field by receiving the recording current to simultaneously record the video signal and the Hi-Fi audio signal on a video track.
To achieve the second object of the present invention, there is provided an apparatus for reproducing a video signal and a high fidelity (Hi-Fi) audio signal recorded on a video track of a recording medium using the same heads, comprising: heads for simultaneously reading the video signal and the Hi-Fi audio signal recorded on the video track; a switching amplifying portion for amplifying the video signal and Hi-Fi audio signal read by the head with a predetermined gain, and for switching the result according to a head switching signal; a band pass filtering portion for passing only the Hi-Fi audio signal of the output signal from the switching amplifying portion; a band rejection filtering portion for rejecting the frequency band of the Hi-Fi audio signal of the output signal from the switching amplifying portion; a Hi-Fi audio signal demodulating portion for demodulating the output signal of the band pass filtering portion; and a video signal reproducing portion for separately demodulating a modulated luminance signal and a modulated color signal included in the output signal of the band rejection filtering portion, and for mixing the separately demodulated signals.